Papyrus tools
These tools are believed to be the same ones that Papyrus used to develop tracks for NASCAR 3, and some of the tools produce files that are 100% compatible with ICR2, others are close enough that third-party conversion tools can bridge the gap. While these programs have been available online since the early 2000s and there is no evidence that their availability has been challenged by the rights holder, they are to be used “at your own risk.”
Dale Earnhardt Jr., Executive Director of iRacing.com, mentioned the use of the Sandbox tool for ICR2 modding in Episode 350 of The Dale Jr. Download podcast on July 27, 2021:
Somebody went on an old Papyrus IndyCar game that was 20 years old and made a track out of a program called Sandbox of what the track [Nashville] is going to look like.
The tools can be found under “N3 Sandbox” on Mistycreek’s page (also found on the Internet Archive). The N3 Sandbox contains many files, but the essential ones are listed below.
| Tool/File | Purpose |
| dos4gw.exe | 32-bit DOS extender that is required for all other .exe files to work |
| sge.exe | Edit the track sections (i.e. positions of the center line along the track) as well as elevations. Produces or updates the output file <track>.sg. |
| sfe.exe | Edit the track features (boundaries and surfaces). Requires an existing .sg file with minimum of a fully connected centerline from SGE. Updates the output file <track>.sg |
| sge.ini | Configuration file for SGE and SFE. |
| sg2trk.exe | Converts a <track>.sg file to a <track>.trk file, which contains data derived from the .sg file and is directly loaded by ICR2 |
| trk23d.exe | Converts a <track>.trk file to a Version 3.0 <track>.3d file, which is the human readable text code defining the 3D model of the track. Trk23D will create each 3D polygon (i.e. x, y, z coordinates of the vertices for each polygon, and the u, v coordinates of any textures) that makes up the walls, track surfaces and fences, and the 3D file itself will be divided into sections, each of which is a small segment along the track containing the walls, fences and track surfaces. |
| 3d23do.exe | Converts a <track>.3d file to a <track>.3do file for NASCAR 2 and newer. This <track>.3do file is used to view the track in the OPE program and cannot be loaded by ICR2. (To make a .3do file that is compatible with ICR2, we use nooRok’s 3d23do converter) |
| ope.exe | View the <track>.3do generated by 3d23do.exe in 3D, load objects and track surface markings. OPE updates the <track>.3d text file, which needs to be recompiled into a <track>.3do file before viewing again in OPE. |
| Other files | These are the files that may be referenced by the .3do file generated by Trk23D and 3d23do, and are needed to load the track in OPE. As other objects and textures are added to the track, those files are also needed to be present in order to load in OPE. asphalt.mip concrete.mip dirt.mip drygrass.mip grass.mip sand.mip wall0.mip … wall5.mip sky.3do + any referenced .mip files horiz.3do + any referenced .mip files sunny.pcx armco0.mip … armco3.mip |
All of the above Papyrus tools must be run in a DOS environment, such as DOSBox or a real/virtual DOS machine.
Community tools
nooRok’s 3d23do
This Python tool has essentially the same functionality as the Papyrus 3d23do, except it will create an ICR2 compatible .3do file.
Last Chance tools
A package of DOS-based utilities for conversions between .MIP, .PCX and .PMP files. Made by Róbert Szikszó and originally released in 2000.
Version 3.2: forum post with link to download
WinMip
A Windows 95 utility that converts .mip, .m16, .mi4, .pbf, .pmp, .p16, .pm4, .srb, .stp files to .bmp, and vice versa. Version 1.2 is the only version that supports .stp files for the track menus. Made by Klaus Hörbrand and originally released in 1998.
Version 1.2: forum post with link to download
Version 2.16.6: Winmip official page via Internet Archive